The front-runner's comment that he cares about Americans but isn't 'concerned about the very poor' is quickly met with criticism from both Democrats and fellow Republicans.

Reporting from Tampa, Fla., Eagan, Minn., and Reno — The Republican presidential contest shifted to the West and Midwest on Wednesday as an exultant Mitt Romney dueled with the man he hopes to meet in November, President Obama, but found himself sidetracked when an infelicitous remark was seized upon by his opponents.

Romney's comment came as he sought, following his landslide win Tuesday in Florida, to cast himself as the inevitable nominee, a posture that had eluded him since his Jan. 21 collapse in South Carolina.

"I'm in this race because I care about Americans. I'm not concerned about the very poor. We have a safety net there. If it needs repair, I'll fix it," he told CNN.

His characterization about the poor immediately metastasized online. Asked about it later, Romney explained, "Of course I'm concerned about all Americans — poor, wealthy, middle class — but the focus of my effort will be on middle-income families who I think have been most hurt by the Obama economy."

Newt Gingrich, a distant second in Florida, sought to take advantage of Romney's wording as he spoke to hundreds of supporters packed into Great Basin Brewing Co. in Reno.

"I am fed up with politicians in either party dividing Americans against each other," said Gingrich, at his first Nevada event before Saturday's caucuses. Drawing a sharp distinction between himself and Romney, he added, "I am running to be the president of all of the American people, and I am concerned about all of the American people."

Romney's comment also drew condemnation from Obama partisans who have repeatedly exploited the candidate's quotes to argue that Romney is out of touch. And Sen. Jim DeMint (R-S.C.), who endorsed Romney four years ago, encouraged him to "backtrack," saying the very poor needed jobs, not welfare programs.

At a rally in Eagan, Minn., on his way to a nighttime rally in Las Vegas, Romney did not mention the three other GOP contenders. Instead, he mocked Obama for recently telling a woman that he found it hard to understand how her husband, an engineer, could not find a job (Obama cited high demand for engineers).

"Is he so detached from reality? Does he not understand what's going on in America?" Romney said.

While Romney was criticizing him, Obama took veiled aim at the Republican front-runner on a potent issue for voters in Nevada. In October, when asked what should be done about the housing crisis, Romney told the Las Vegas Review-Journal: "Don't try and stop the foreclosure process. Let it run its course and hit the bottom."

The president, not mentioning Romney's name, told an audience in Falls Church, Va.: "It is wrong for anybody to suggest that the only option for struggling, responsible homeowners is to sit and wait for the housing market to hit bottom. I refuse to accept that, and so do the American people."

Obama also highlighted the housing crisis in Nevada, a key swing state that he won in 2008, as he proposed a new plan to help homeowners. "In places like Las Vegas, more than half of all homeowners are underwater — more than half," he said.

Although there are no recent Nevada polls, Romney is favored to place first in Saturday's caucuses. He won 51% of caucusgoers when he ran in 2008, partly due to support from the large number of fellow Mormons there. Romney trailed Gingrich in most nationwide polls after his loss on Jan. 21 in South Carolina, but Gallup reported Wednesday that he now led Gingrich, 31% to 26%.

The president's campaign team disparaged Romney's Florida victory in a memo that mocked his advertising as hitting a historic high for unrelenting negativity. But it also highlighted the negative approach the president himself could take if Romney is the nominee, calling him "a corporate buyout specialist who as governor drove his state to 47th in job creation."

With Romney heading to Nevada, Stephanie Cutter, Obama's deputy campaign manager, said that the Republican's "lonely support" of the proposed Yucca Mountain repository for spent nuclear fuel "will continue to repel the very voters who will decide the White House."

The Obama administration decided in 2009 to halt work on the unpopular project. Romney counters that the president has allowed politics to trump science, noting that studies had concluded the site was safe. He has said the federal government should offer enticements to Nevadans to back the project, which has cost $15 billion, but should not "jam it down their throat."

Ron Paul, whose libertarian views, ardent young supporters, statewide organization and television advertising could boost him in Nevada's caucuses, spoke in Las Vegas to Hispanics in Politics, a nonpartisan organization that is home to many Democrats who can't caucus on Saturday.

The Texas congressman spent much of his talk thinking aloud about the thorny issue of immigration. He offered few specific proposals, but suggested the United States should stop policing the border between Afghanistan and Pakistan.

Rick Santorum was the only candidate who did not campaign in Nevada on Wednesday. He was stumping in Colorado, which votes Tuesday, as do Minnesota and Missouri.

"You've got to stand up and ignore all of this inevitability and say we want somebody who can actually voice our values," the former Pennsylvania senator told a breakfast meeting of the Arapahoe County Republican Men's Club at a Mexican restaurant in Denver.

Santorum attacked both Romney and Gingrich as insufficiently conservative. In response to a question about how a social conservative could win the White House, Santorum said he shared the same positions that his opponents espoused. "What makes me a social conservative and them not?" he asked. "Well, I'll tell you the difference: I actually believe it."